Method of controlling articulated robot

Abstract

A method of controlling an articulated robot having in excess of six axes and up to twelve axes, comprises the steps of dividing the axes into two groups each composed of six axes or less, those axes which are positioned on one side of a dividing point (P) closely to a reference point serving as redundancy axes (11), those axes which are positioned on the other side of the dividing point closely to a robot wrist (Q) serving as basic axes (12), and controlling the dividing point (P), as a first control point, by way of interpolation and controlling the robot (Q), as a second control point, by way of interpolation with the controlled first control point regarded as a new reference point, so that all the axes of the articulated robot can be controlled by way of interpolation.

We claim: 
     
       1. A method of controlling an articulated robot having more than six axes and up to twelve axes, comprising the steps of: dividing the axes of the robot into a first group comprising six axes or less positioned on one side of a first control point on said robot which is a side of said robot where a reference point of said robot is positioned, and a second group comprising six axes or less positioned on the other side of said first control point which is a side of said robot where a robot wrist is positioned, said robot wrist defining a second control-point on said robot, said first group of axes serving as redundancy axes and said second group of axes serving as basic axes;   controlling the first control point of said robot based on said reference point by performing an interpolation calculation to provide for an interpolated motion of said first control point; and   controlling the second control point of said robot to control the robot wrist by performing a further interpolation calculation based on said first control point which serves as a further reference point to provide for an interpolated motion of said second control point.   
     
     
       2. The method of claim 1, comprising the further steps of: calculating rotational angles of the axes of said robot; and   simultaneously controlling the movement of said axes based on the calculated rotational angles.